Thank you all for responding and giving valuable suggestions to my code.
I sorted out the problem in seeing some outputs in modelsim.
But the main problem I observed with my code is, it is not synthesizing. I am not able to view the design in the Technology map viewer except two pins (clk, rst) in the QUARTUS II 11.0, but I can see the complete design in the RTL viewer in the QUARTUS II 11.0.
After compiling the code I observed the message in the info that
"Info: 102 registers lost all their fanouts during netlist optimizations".
Can anyone please tell me how to solve this problem and keep all my sub-modules without optimizing.